How object storage works
Unlike file storage systems that organize data into a hierarchy, object storage stores data objects in a flat system. These objects then are referenced and retrieved using a Universally Unique Identifier (UUID) or Globally Unique Identifier (GUID) of 128-bit integers, significantly large enough to allow for a wide range of unique IDs, important because of the large number of objects stored.
Also unlike file storage systems, object storage uses metadata linked to data objects via UUIDs to find user requests. Files on the other hand retain very little metadata, relying on the hierarchy to locate requested data. The main advantage, object metadata allows for extensive (unlimited) description of the object, for example, video files can include lists of cast and crew. So, a user can locate video files by actor name.
Hierarchical file storage systems run into difficulties when scaled to capacities ranging in the petabytes. At this size, file storage performance degrades considerably, and the common solution is to split data into logical unit numbers (LUN), or collections of physical or virtual storage devices. While this improves storage performance, it also adds more complexity, until the complexity begins to cause difficulties as well. Instead, metadata search capabilities are used to overcome the scaling of data, and the ensuing technical challenges that crop up in file storage.
Object storage reliability is further enhanced by the technique of Erasure Coding. In essence, Erasure Coding volumes divide data into fragments, or shards, each is packed with error correction data, and then each are placed on different disks. By diversifying the data and packing it with redundant information, it ensures that files can be restored even after many disk failures. In short, Erasure Coding is a modern RAID system.